Lamp focusing mechanism



Dec. 30, w30. s. F. AREUCKLE LAMP FOCUSING MECHANISM Filed Nov. 30, 1925INVENTOR JAM/EL ARBUCKLE y z y f u ATroRNEY Patented Dec. 30, 1930UNITED STATES vPATENT OFFICE SAMUEL .AR-BUCKLE, OIE HIGHLAND PARK,MICHGAN, ASSIGNOR TO MONOGRAM'. LENS CORPORATION, OF NEW YORK, N. Y., ACORPORATION 0F DELAWARE LAMP FocUsIirG MECHANISM Application ledNovember 30, 1925. Serial No. 72,106.

This invention relates to lampfocusing mechanism. M-ore particularly,the invention relates to focusing mechanism adapted for use in electricheadlamps for automobiles or similar automotive vehicles whereby thetilament ot the electric lamp is adjusted to give maximum lightingefficiency.

In my co-pending application, Serial No. 13,681, iled March 7, 1925, Ihave shown and described mechanism basically similar to the subjectmatter of the present application, in which both axial and verticaladjustment of the filament of the electric light bulb positioned in thelamp is secured. In this copending case, use is made of a transverselymovable plate connected to the lamp socket which is pivotally mounted inthe reflector, said plate having plural adjusting means eX- tcnding tothe rear of the casing. In my c0- pending application, Serial No.51,557, filed August 21, 1925, I have disclosed an improvement over theprior filed application in which pivotal movement of the socket of theelectric lamp is secured by means of a screw Abolt and a rack andpinion, the screw bolt imparting axial adjustment to the socket, and theoperationof the pinion on the rack causing a transverse verticalmovement of the socket.

The present invention is an improvement over the specic devices shown inthe above mentioned co-pending applications and consists in the use of apivoted socket, adjustment of which is secured by means of an axiallymovable screw for the axial adjustment, and by means of a cam mounted onthe casing and in engagement with the socket plate for impart-ingtransverse movement to the socket.

Among the objects of the invention is the provision of adjustingmechanism which is exceedingly simple in construction and in operation,involving the smallest possible number of parts. Another importantobject is the utilization of frictional means for holding the socket inadjusted position. An object of the invention also is to simplify themeans for causing transverse vertical movement of the adjusting plate,.said means including a cam rotatably mounted on the casing and inengagement with the adjusting plate.

An object also is the provision of lamp adjusting mechanism which isparticularly adaptable to the focusing of a two ilament lamp Within areflector.

Various other objects relating to the relationship of the adjustingmeans, the construction of the adjusting plate, the devices for securinga strong frictional hold of the movable parts, and factors bearing onthe mode of assembly and method of manufacture will become apparent uponconsideration of the description hereinafter detailed, and on inspectionof the accompanying drawing, in which Figure 1 is a vertical, sectionalelevation o a headlamp showing the adjusting mechanism;

Figure 2 is a detail, showing the adjusting plate and the cam mechanism;

Figure 3 is another detail of the adjusting plate;

Figure 4 is a perspective of the adjusting plate showing the connectionto the cam; and

Figure 5 is a perspective of the base of the lamp showing the wiringarrangement of the double filaments employed.

The invention, as previously indicated, has special adaptation for usein automobile headlamps and for purposes of illustration, the inventionis described as applied to the ordinary type of automobile headlamp.Figure 1 shows a headlamp 10 having a cylindrical casing 11, the frontend of which is open and the rear face of which is closed by acurvilinear shell 12. The front edge of the casing 11 terminates in aninwardly directed flange 13 which is designed to contact with andsupport the relector 14.

To this end the reflector 14, which is of the ordinary paraboloid type,has its forward edge terminating in a radial flange 15, the outerperiphery 16 of which is adapted to engage with and be held 'by thecasing iiange 13, hereinabove mentioned. The reiector is held inposition, as 's cifed, by means of a pivoted door member 1 which haspivotal engagement with the casing at 18 by means of the door prong 19and casing hook 20, and which is secured in position by the bolt 21passing through the door member 17 and the opposed reilector and casingflanges 16 and 13.

lsource is a The door member 17 is annular in formation and possesses abackwardly directed flange 22 which is adapted to have bearing on aridge 23 formed on the lens 24 of the reflector, as shown clearly inFigure l of the drawing.

Intermediate the outer edge of the lens and the reflector flange 15 ispositioned the usual cushioning cord 25 which normally rests in theannular groove 26 on the fron side of the flange l5.

It is thus seen that with the reflector cushion cord lens and doormember 17 in position f asheld by the bolt 21, a unied, stable and rigidassembly is accomplished, suitable for automobile use.

rlhe lamp bulb socket is positioned in an aperture formed in the axis ofthe reflector. As shown, the socket 30 is mounted so as to have eitheraxial or pivotal movement in the aperture 31. The open socket end of thesocket 30 extending within the reflector is formed with bayonet slots 32adapated to receivel the pins 33 mounted on the base 34 of the lamp bulb35.

The lamp bulb as shown is of a special type having two filaments 36 and37 positioned one above the other and adapted to be focused in thereflector so that they are equally displaced from the axis of thereflector and at the same 'time each lying approximately within thefocal plane of the reflector. The forward spherical glass portion of thebulb is preferably constructed with annular variations in thickness, asshown, to produce the annular rings 38 the purpose of' which is to breakup the forma-tion of an image of Aeither filament brought about byreflection from the interior surface of the bulb. Figure 5 clearlybrings out in perspective the construction of the filaments and thewiring of the lead-in wires. in relation to the socket of the bulb. Asshown, the filaments 36 and 37 are of the coiled-V type so as to give aconcentrated light source. These filaments are pla-ced one above theother and in symmetrical relation one to the other'. The filament 36 iselectrically'c'onnected to the base`contact by wire 34, bythe commonwire 44 so that only two base contacts are necessary for this lamp.v

The socket 30, lon its back end, contains the spring iheld connectingpins 45'which end in the terminals 46. The flexible cord 47 conncts theterminals 46 tothe casing plug 48, at which electrical energy from anexternal lied to the electric circuit.

The spec cvadjusting mechanism will now bedescribed. Fastened by anyappropriate means tothe upper side ofthe socket 30 is a plate 50 havingup'turned members 51 and 52,each of vwhich is threaded to receive theaxial adjustment screw bolt 53. This bolt andere is threaded throughboth plates 5l and 52 and is prevented from removal by the cotter pin 54extending through the end of the bolt. The bolt backwardly extends tothe exterior of the casing through the shell l2 and terminates in ascrew head 55 having a transverse notch 56 for manipulation of the same.

At the point where the bolt 53 passes through the casing, the casingmaterial is struck or pressed inwardly and slotted to form a forwardlyextending depression with opposed wings 57 and 58 separated by the slot59. The slot 59 has an enlarged portion 60 of a width approximately thatof the diam` eter of the bolt 53, and this enlarged slot portion 60 alsohas an extended length so as to permit vertical adjustment of the bolt53 within defined limits. The bolt is frictionally maintained in itsposition by means of a coil spring 6l which extends between theupstanding portion 52 of the socket plate 50 and a washer 62 adjacentthe 'slotted wings 57 and 58.

ln addition, a yieldable metallic plate 9 is fastened to the plate 50 atone end, the other end being free to move, and the middle portionthereof being humped and slotted so that the sides of the slot havefrictional bearing against the screw bolt 53 and tend to hold the samein adjusted position.

It is evident that rotation of the screw head 55 will cause axialmovement of the socket 30 by reason of the connections and agenciesabove identifiedv and described.

Mechanism for producing vertical movement of the lamp bulb socket isutilized as follows. Referring particularly to Figures 2, 3 and 4, thereis shown the adjusting plate 70, this being of approximately rectangularformation vand having a tongue member 71 extending from one edgethereof. The material of the plate is such as to permit a certain degreeof flexing, and thewidth of the tongue 7l is such that it may beinserted back of the Wings 57 and 58, andin front of the casing aboveand below the slotted portion, as clearly disclosed in Figure 2 of thedrawing. There is an aperture 7 2 formed 'in the tongue which is of asize sufiicient to receive the adjusting bolt 53. Y

vThe body` ofthe plate is formed with two struck-out tongues 73 and 74,as shown in Figure 4, to form fiat opposing surfaces extending'transversely to the axis of the plate, as determined by the tongueextension 71. VThetongues 73 and 74 are on'one side ofthe plate and areconnected by a central axial slot 75. When in position with the bolt 53in the aperture 72 of the tongue 71, the slot is adapted to rest on theforward side of the casing wall surface immediately adjacent an aperture76 in which a bolt 77 is positioned. vThis bolt has an adjusting head78, and the shank of the bolt extends through the slot of the adjustingplate and is held in position by the Washer 79 and nut 80. 1

Intermediate the forward face of the plat-e 70 between the tongues 73and 74 is mounted a circular cam member 8l having an aperture 82 ofrectangular formation therein adapted to conform to a portion of thebolt 77 so that a rigid connection exists between the cam and the bolt,and on rotation of the bolt the cam is correspondingly rotated. Thediameter of the cam 8l corresponds approximately to the distance betweenthe tongues 73 and 74 so that irrespective of the point of rotation ofthe cam, there will be constant bearing on both sides by the tonguesagainst the edge of the cam. Attention is directed to the transverseWidth of the tongues 73 and 74 which is of sufiicient extent so that thepoints of Contact of the cam against these tongues is continuous, as thecam is rotated. This is of importance in the construction as preventinglooseness and rattle, and inability to properly hold the focus of thelamp bulb.

It may be noted further thatin the assembly of the adjusting plate 70 inposition on the curvilinear shell Wall 12, it is forced out of itsnormal fiat position into a state of strain, which tends to maintain astrong frictional bearing between the plate and the casing shell. Thisfrictional bearing is of importance in maintaining the final adjustmentof the lamp bulb filaments when once secured, and obviates the useofauxiliary holding means.

The operation of the mechanism as described will now be referred to.

With the parts assembled as shown in Figure l with the lamp bulb inosition, axial adjustment of the lamp bulb 'laments is secured brotation of the screw bolt head 55, whic i rotation, depending upon thedirection, causes axial movement of the socket 30 and lamp bulb 35. Inaccordance with usual focusing methods, the operator may readilydetermine when the filaments are approximately in the focal plane of therefiector. Adjustment is then made to bring one filament above and theother below the axis of the reflector, and equally spaced therefrom.rIhis adjustment is secured by the rotation of the bolt head 7 8 whichcauses rotation of the cam 81 and a resultant vertical movement of theadj usting plate 70 with the connected bolt 53 and socket 30. The socketpivots in the aperture 31 and consequently the filaments are shiftedvertically until their arrival at the desired position. After thisprimary adjustment, a secondary adjustment may be made at both boltheads until the filaments of the lamp bulb are in the proper focalposition.

Among the advantages of the construction above described may bementioned that resulting from the possibilty of continuous rotation ofthe cam 81. In prior constructions it has been proposed to use means formovlng the adj Listing plate which had limiting stops, and the operator,in manipulating the adjustment, frequently would exert too greatforce'on the Listing means, not realizing that the limiting point hasbeen reached, and thereby causing breakage of the parts. In thisconstruction, as above presented, there are no stopping devices, the cambeing freely rotatable. Another outstanding advantage of theconstruction resides in the continuous contact of the cam against theadjusting plate members which practically eliminates all lost motion andtherefore permits very close adjustment of the lamp filaments. This isespecially advantageous in the use of a two filament bulb, as variationof a small fraction of an inch of' the distance of these filaments fromthe paraboloid axis frequently causes serious distortion of the emittedlight beams.

Note should be made of the fact that while a two filament lamp isspecified and described in connection with the adjusting means, that theinvention may be employed with effectiveness for any type of lamp bulbsuch as the ordinary one filament lamp.

Various modifications of the invention other than those hereinabovespecified may be made by those killed in this art, and consequently itshould be understood that the disclosure is illustrative rather thandefinitive, the scope of the invent-ion being defined by the claimshereunto appended.

I claim as my invention:

1. In lamp adjusting mechanism, the combination of a casing; a reflectorpositioned Within the casing; a socket positioned in an aperture formedin the aXis of the refiector; a lamp bulb within the socket andreflector; means for axially adjusting said bulb Within the reflector;means for vertically adjusting said bulb Within the reflector, said lastmentioned means-being operable from without the casing and comprising aresilient plate connected to and movable with said axial adjusting meansand adapted to have a normal curvature different from that of thecasing, said plate being insertable intermediate a struck-out adjacentportion of the casing and .a non-struck-out portion of the casingWhereby the resilient plate is maintained in flexed position producingfrictional contact with the casing.

2. .In a lamp adjusting mechanism, the combination of a casing, the rearWall of which has a portion therein struck out in a forward directionand slotted; a refiector within the casing; a lamp bulb socket movablein an aperture formed in said refiector;

and mechanism for vertically and longitudinally adjusting said socketcomprising an adjusting plate positioned behind said struckout portionof the casing and having ends terminatingon either side of saidstruck-out portion and in front of the rear casing adjacent thestruck-'out portion; an adjusting screw extending through the slot ot'the struck-out portion and through an aperture termed in 'j J- J- samadjusting plate, the head of said screw terminating on the outside oi"said casing to permit rotation thereof; means for transversely movingsaid adjusting plate; and a screw-threaded member adapted to havethreaded engagement with said adjusting screw, said member being fixedto the socket, said adjusting plate being resiliently maintained indeformed position against said casing by said struck-out portion wherebyis 'frictionally retained movement relative to the casing.

3. ln a lamp adjusting mechanism, the combination of a casing, the rearwall o which has a portion therein struck out in a forward direction andslotted; a reflector within the casing; a lamp bulb socket movable in anaperture Jformed in said reflector; and mechanism ii-'or vertically andlongitudinally adjusting said socket comprising an .adjusting platepositioned behind said struck-out portion ot the casing and' having endsterminating on either side of said struck-out portion andvin iront otthe rear casing adjacent the struck-out portion; an adjusting screwextending through the slot of the struck-out portion and through anaperture formed in said adjusting plate, the head of said screwterminating outside ot said casing to permit rotation thereof; means fortransversely moving said adjusting plate a screw-threaded member adaptedto have threaded engagement with said adjusting screw, said member beingfixed to the socket; said adjusting plate being resiliently maintainedin deformed position against said casing by said struck-out portionwhereby it is frictionally retained from movement relative to thecasing; and resilient means intermediate the casing and threaded memberadapted to maintainthe adjusting screw to the limit of its'forwardmovement. v

4. In a lamp adjust-ing Amechanism, the combination of a. casing, therear wall of which has a portion therein struck .out in a forwarddirection and slotted; a. reflector within the casing; a lamp bulbsocket movable in an aperture formed in said reflector; Aand mechanismfor vertically and longitudinally adjusting said socket comprising anadjusting plate positioned behind said struck-out portion of the casingand having ends terminating on either side of said struck-out portionand in front of the rear casing adjacent the struck-out portion; anadjusting screw extending through the slot of the struck-out .portionand through an aperture formed in said adjusting plate, the head of saidscrew terminating on the outside of said casing forpermittingrotationthereof; means for transversely moving said adjustingplate; a screw-threaded member adapted to have threaded engagement withsaid admear-.i4-

justing screw, said member being fixed to the socket, said adjustingplate being resiliently maintained in deformed position against saidcasing by said struck-out portion whereby it is iirictionally retainedfrom movement relative to the casing; resilient means intermediate thecasing and threaded member adapted to maintain the adjusting screw tothe limit ot its forward movement; and trictional means for resistingrotational movement of the adjustii'ig screw.

5. lin a lamp adjusting mechanism; the combination ot casing, the rearwall ot which has portion therein struck out in a forward direction andslotted; a reflector within the casing; a lamp bulb socket movable in anaperture "formed in said reflector; and mechanism for vertically andlongitudinally adjusting said socket comprising an adjusting platepositioned behind said struckout portion ot the casing and having endsterminating on either side of said struckout portion and in iront of therear casing adjacent the struck-out portion; an adjusting screwextending through the slot of the struck-out portion and through anaperture formed in said adjusting plate, the head ot said screwterminating on the outside ot said casing for permitting rotationthereof; means for transversely moving said adjusting plate; ascrew-threaded member adapted to have threaded engagement with saidadjusting screw, said member being fixed to the socket, said adjustingplate being resiliently maintained in deformed position against saidcasing by said struck-out portion whereby it is rictionally retainedfrom movement relativev to the casing; resilient means intermediate thecasing and threaded member adapted to maintain the adjusting screw tothe limit of its forward movement; a cam, rotatably mounted on thecasing and comprising i an eccentrically mounted disk, and tonguesprojecting from the adjusting plate, said tongues forming continuousbearings with the edge of the cam disk.

6. In a lamp adjusting mechanism intermediate the lamp socket and a lampcasing containing said socket, the combination of a casing having aslotted section thereof adjacent the axis of the socket stamped inwardlyto form a bridged member on a plane displaced interiorly from the planeof the casing; a resilient adjusting plate adapted to have a normalcurvature diiierent from that of the casing insertable behind saidstamped portion and in front of the adjacent portions of the casing,said plate being frictionally held from movement by the pressure of theplate against the stamped inward portion and the adjacent casing wall; ascrew engaging member fixed to the socket; an adjusting connection screwpositioned in an aperture of said plate and in said slot and extendingtoward said socket, the head of the meeste screw extending to the rearside oit the plate and operable from the exterior of the casing, and theforward threaded portion of this screw having threaded engagement Withthe threaded member fixed to the socket; means for maintaining saidscrew in threaded relationship With said threaded member; and means fornormally maintaining said screw at one limit of its axial movement, saidscrew being rotatable to give axial movement to the socket; and saidscrew being transversely movable to predetermined adjusted positions;and a cam rotatably mounted on the casing and contacting With theadjusting plate adapted to cause transverse movement ot said plate andattached screw.

7. ln a lamp adjusting mechanism, the combination of a casing having acurved rear Wall, a portion of said Wall being struck inwardly therefromand having a slot therein, a releotor Within said casing having anaperture through the axis thereof, a lamp socket movable Within theaperture in said reflector, a lamp bulb in said socket Within saidretiector, a resilient plate slidably mounted on the rear Wall of saideasing and held in friotional contact therewith by said streek-inportion, said plate being inserted between said struck-in portion andthe rear Wall or said easing, a screw-engaging member attached to saidsocket, a screw rotatablT mounted in an aperture in said plate passingthrough the slot in said struck-in portion or said casing wall andengaging said member whereby rotation of said soresv atl'eots Y.axialmovement oi' said socket and ballo, said sore-a7 har/*ing a headterminating on 'the outside or said plate to permit rotation of saidsorevv, a pin rotatably mounted on said easing and having headterminating on 'the outside thereof to permit rotation ot said pin, adise ecoentrically attached to said pin, and a pair of horizontalparallel tongues attached to said plate and confining said dise wherebyrotation or said pin causes the reoiprooation of said plate and verticalmovement ot said bulb.

Stn testimony whereof, l ami; my signature.

SAMUEL ABBUCKLE.

